玉树地区1961—2015年降水变化特征分析

Precipitation Variation Characteristics in Yushu in 1961-2015

为了解玉树地区近55年来降水的变化特征和规律,利用玉树地区近55年降水量资料,分析玉树地区降水量年代际、年际、各季和各月的气候变化特征,并用小波变换方法分析年、季降水量的周期变化。结果表明,年降水量呈增加趋势,气候倾向率为4.641 mm/10 a,55年来共增加25.5 mm。夏季降水量呈减少趋势,而春、秋、冬季降水量呈增加趋势;各月降水量减少最多的是7月,其次是8月;各月降水量增加最多的是5月,其次是6月。年、春、夏以及冬季降水量的主周期是26年左右,秋季降水量的主周期为12年左右。

The paper aims to understand the variation characteristics and regularity of precipitation in Yushu in recent 55 years.The climate change characteristics of decadal,annual,seasonal and monthly precipitation in Yushu were analyzed based on the observed precipitation data during 1961-2015;the periods of annual and seasonal precipitation in Yushu were also analyzed by using the wavelet transform method.The results showed that：the annual precipitation increased with a tendency of 4.641 mm per decade,the increased rainfall was about 25.5 mm;the precipitation in summer showed a decreasing trend,while the precipitation in spring,autumn and winter increased;the maximum decrement of precipitation was in July,followed by that in August;the maximum increasing amount of precipitation was in May,followed by that in June.The precipitation of year,spring,summer and winter had a main periodicity of 26 years,precipitation in autumn had a main periodicity of 12 years.